Hay Storage


Storing round bales indoors can be a challenge.

Avoiding hay loss is important to both the farmer and horse person, and especially so in times like these when a dry summer has minimized hay production. Hay loss in the form of spoilage or destroyed nutrients is the last thing we need. When every bite counts, proper storage is a must.

Weathering destroys hay and its nutrients. Moisture ruins hay; it produces mold and promotes decay, and also causes overheating in the curing process. Exposure to sunlight and excessive heat destroys hay nutrients. Minimizing the light, heat, and moisture exposure will help minimize loss. Unless all surfaces of the haystack are against a solid surface or wall, there will be sides exposed to the elements.

While some circumstances make outdoor storage and plastic wrapping of hay feasible, storing hay inside a barn or shed is ideal, especially for horses. A good hay storage facility should provide protection from rain, but be open enough to breathe. Good air circulation allows damaging heat to be dissipated, and bales should be stacked to allow airflow while maintaining stability. Small openings along the underside of the roof can encourage air circulation. Screening along the openings would allow the air to continue to circulate but would deter rain and snow from blowing up through them.

The time for field curing depends on weather conditions and mechanical handling at cutting. Low relative humidity, high air temperature, and good air movement around the cut forage all accelerate the rate of drying. Because leaves of cut herbages lose water more rapidly than stems, mechanical conditioning (crushing or crimping) can help to reduce the time required for curing, especially for legumes like alfalfa.


Moisture destroys

The amount of moisture remaining in the hay at baling is critical. Moist hay can develop mold, and moldy hay should never be fed to horses. Colic can result, and mold spores can create and aggravate respiratory problems. Mold-creating organisms generate heat through their own respiration, reducing hay quality and making the dry matter less digestible.

Too much moisture ruins the quality of the hay and it can also be very dangerous. Excessive moisture is frequently the cause of barn fires. Putting high-moisture hay in a stack is an invitation to fire. (Maximum moisture percent at baling depends on the area of the country - 17% maximum is recommended in some areas, 20% for others.) Wet hay molds quickly and heats, then spontaneous combustion can occur - within two or three days, or as long as 3 weeks, after hay is stored. A barn fire would be a tremendous loss and is always a valid fear for the haymaker. Therefore, special care is needed if hay is not thoroughly dried or becomes wet. The hay should be spread out to dry quickly and turned often as it is drying.

Hay storage areas should be monitored often for pungent odors, hot damp areas on the stack, emission of water vapors, and other signs of heating. If there is any doubt, determining the temperature of the hay is important. To check the stack's temperature, one can drive a narrow, sharp-pointed pipe down into the hay, then lower a high-range thermometer inside the pipe and leave it there for about 20 minutes. Make the reading quickly when the thermometer is retrieved.

Hay producers are warned to closely watch (on a daily basis) any hay that has reached 150 degrees, to inspect hay at 160 degrees every four hours, to keep an adequate water supply on hand, and to request the fire department to stand by if hay has reached 175 degrees, which is the point at which hot spots and fire pockets are possible. It is recommended, when possible, to remove hay that has reached 185 degrees. (It must be removed with great caution and deposited a safe distance from buildings because flames may develop when air comes in contact with the hay.) At 210 degrees, hay is almost certain to ignite. This is obviously a dangerous situation.

The unseen danger in all this is that the fire pockets that may develop will form inside the stack and are not easily detected. Nobody should enter the mow alone, and it is recommended that planks be placed across the top to walk or crawl across when checking the stack. Heavy ropes should be worn around the waist because of the danger of falling into a fire pocket.

Hay packaging

Snow in the loft - good ventilation, but poor protection from the weather.

Large round bales can be an economical purchase for small and large operations alike if one has the storage space for them - their shape does not afford the most efficient use of space. If the bales are properly wrapped in plastic, they can be stored outside until ready for use. In some climates, round bales are successfully stored outside and unwrapped - the rain is shed much like a thatched roof. Round bales that are baled tightly have less loss than round bales put up loosely. The majority of the outside layer losses occur at the bottom of the bale where it comes in contact with the soil. This layer would need to be discarded and the inner layers closely inspected before feeding.

               Round bales are heavy (500-1200 pounds, depending on size, tightness, and hay type) and not easily maneuvered without equipment. Getting them into storage and into position for use takes some effort. Once in a convenient spot and on its side, a roll can be opened and easily peeled. The amount of hay needed can be torn off with a pitchfork and fed individually, or an entire bale may be placed in a feeder.

Large rectangular bales afford a more efficient use of space in storage, and better shape retention during storage. Indoor storage is best because they do not shed water. At a weight of about 700 pounds each, they too are difficult to move and require equipment. Yet the lower price may be worth the trouble.

Small rectangular bales, about 40 to 60 pounds, are easily handled. Pricier but convenient, this is the most commonly used package. Baling twine or wire adds up more quickly, but can be composted or recycled.



  • Stack bales on the cut edge for the best drying and reduced spoilage.
  • Store hay in a well ventilated but dry storage area. Exposure to humidity is not a problem as long as there is good ventilation.
  • Store hay on a dry, wood floor, on wood pallets, or on tires. Don't store hay on concrete or directly on the ground because it can absorb ground moisture and cause mold and rot.
  • Keep hay out of direct sunlight. If exposed to the sun, the outer edges of the bale can become bleached. Bleaching results in a lack of color and a lack of vitamin A/carotene. (Even when kept in ideal conditions, the outside of a bale will lighten in color. However, when it is broken open to feed, the center will be just as fresh as when it was baled.)
  • Avoid breaking open the bales unnecessarily.

When properly stored, hay of any shape or form can keep its quality and freshness longer. It can be stored for one to two years without losing more than 15 to 20% of its nutrients. Choosing good quality hay for your horse will not be a wasted effort and investment if it is properly protected in storage.